Art of sterile packaging



D- 3, 1940- H. F. w'rx-:Rs

ART OF STERILE PACKAGING Filed June 4, 1940 2 Sheets-Shea?l 1 IN VENTOR. HHH/f? Y A' WH 7.5/95

HTTOR/VEY `D-`3, 1940- H. F. WATERS 2,223,754

ART OF STERILE PACKAGING Filed June 4, 1940 2 sheets-sheet 2 I INVENTOR.HHRRY FWHTE/Y' BY ngel* FITTOR/VE'Y Patented Dec. 3, 1940 UNITED STATESPATENT OFFICE 16 Claims.

The present invention relates tothe packaging art, and, moreparticularly, to the art of packaging materials, including solid andliquid foodstuffs, in a sanitary and sterile manner.

As .those skilled in the art know, collapsible packages and containersmade of paper and of similar iiexible materials were used to an everincreasing extent in the past, Generally speaki ing, these collapsiblecontainers comprised a bag for holding the material to be packaged. Thisbag or envelope was frequently inserted into a carton to furtherreinforce the sam'e and to impart a generally rectangular form thereto.This type of packaging offered great advantages, particularly when itwas desired to package materials in such a manner as to hermeticallyseal them against the effect of external influences. In this case,generally, a fluid-tight and fusible liner was employed for making theinner container and bag and this/liner was hermetically sealed by meansof heat fusion of the fusible material or layer thereof. It has beenfound that containersof this type can be successfully employed even forpackaging liquids.

'Ihe principal advantages of these huid-tight containers resided intheir low` price, great strength and attractive appearance. In addition,this type of container could be shipped in a knock-down or collapsibleform, whereby a very substantial saving in shipping space and cost couldbe obtained. While thesevrluid-tight collapsible containers practicallyrevolutionized the packaging industry, some difliculty was experiencedwhen packaging certain foodstuffs which have to be maintained in thecondition of extreme purity. Such was the case particularly in packagingmilk where it is imperative to maintain thel milk in a completely pureandsterile condition. As is known, milk is an ideal breed- 4o ing groundfor microorganisms of the most varied type and contamination of the milkcauses great danger to the health of the consumer, including childrenand infants, having a relatively low resistance to infectious diseases.Ihis proh-` lem was relatively simple to solve in the case ofconventional milk bottles which could be sterilized before filling atvhigh temperatures. By carefullcontrol of the manufacturing process, itwas possible to obtain the initial purity and sterility of collapsible'containers; there was no guarantee, however, against the` introductionof germs, micro-organisms and other deleterious agents of an organic orinorganic character into the interior of the container during the timeinterval which elapsed between manufacturing the i container and fillingthe same., Due to the fact that the laws regulating the distribution andsale of milk and similar commodities are extremely severe, a seriousproblem existed in the packaging art in connectionxwith the manufactureand use 5 of collapsible milk containers.

It is an object of the present invention to provide a solution -for theoutstandingproblem and to provide the art with a collapsible containerfor milk, and the like, which is capable of maintainl0 ing at least thesame high standards of purity and sterility as may be maintained -atpresent ,with conventional milk bottles.

It is another object of the present invention toY provide a method ofsterile packaging which posil5 tively prevents the entrance oi'deleterious organic or inorganic impurities into the interior of thecontainer intended for shipping and distributing milk and similarcommodities.

It is-a further object of the present invention 20 to provide a noveland improved method of aseptical packaging which involves hermeticallysealing the packaging medium immediately after it is manufactured,maintaining such seal until such time as the package is illled with thecom- 25 modity to be distributed, and thereafter re-sealing suchpackage.

Still another object of the invention is the provision of a novel andimproved collapsible container which may be readily and hermetically 30sealed during its manufacture Yand which may be readily opened toperform the filling and re-sealing operation whereby said container ismaintained in the time interval between its manufacture and ultimate usein a sterile and hermetically sealed condition.

' The invention also contemplates a novel collapsible container for thepurpose of aseptical packaging of foodstuffs', therapeutic agents,surgical cotton, and the like, which is simple in fm structure and whichmay be readily manufactured on a practical and commercial scale at atainer embodying the invention'vl during one of its preliminary steps ofmanufacture in which the two halves of the carto'n blank and layer arefolded together and the resulting envelope is heat-` sealed; i-

liig.y 4 is a perspective view of the container of the invention in itsfinished and collapsed condition ready for shipment and storage;

Fig. 5 illustrates a perspective view of the container of the inventionin its squared-up condition and ready for the filling operation;

Fig. 6 depicts a similar View of the container lhaving theA mouthportions of the inner envelope or bag flattened into `a face to facerelationship;

Fig. 7 shows a perspective view of the container with the top marginalportions of the inner bag bent upwards for the purpose of hermeticallysealing the content thereof;

Fig. 8 is a similar view of the container after the heat-sealingoperation showing the resulting tabs folded towardsv each other, theflaps of the carton being illustrated in their opened condition forreasons of clarity.

is rendered impossible because even though such matter might be of amicroscopic character, the hermetic seal will offer an effectiveobstacle against their entrance. Thus, while in prior practice theinterior of collapsible containers was exposed to germs, and the like,during shipment and storage, such contamination of the container isrendered impossible by my invention.

My invention may take various forms in accordance with the type ofcontainer contemplated. Thus, in the simplest case where the collapsiblecontainer is of the heat-sealed envelope type, I prefer to employ aflexible sheet which is fluidtight and fusible on at least one face.thereof and is folded over along a medial line to bring its edges intoregistering position. This operation leaves three open edges which maybe individually heat-sealed by' applying heat and pressure along anarrow marginal strip thereof. In most cases, however, it is preferredto apply this heat-seal simultaneously to al1 of these three marginalportions in .the shape of a continuous and U-shaped heat-seal whichhermetically seals the interior of the envelope against externalinfluences. In this condition the envelope may be preserved in a sterileand unaffected condition,

indefinitely. When it is desired to ll this envelope with material ofany description, a restricted opening may be made therein or forexample, a

Anarrow strip including one of the heat-sealed seams maybe cut off toprovide a filling opening.

Through this filling opening the contents may bel introduced and thenthe envelope maybe resealed. As a rule, it will be preferred to employan envelope or bag in combination with an outer supporting carton whichimparts additional strength to the inner bag or envelope. vIn myapplication,

to which a liner fusible on at least the top surface thereof isadhesively secured. The carton blank .3

and the liner are so constructed and arranged that manipulating andfolding the carton along predetermined score lines will cause folding ofthe liner into a position in which it may be heatsealed while it isstill resting on the carton blank. While'in prior practice this foldedliner was heatsealed along only two of its edges to retain a fillingopening, in accordance with the present invention the folded liner iscompletely sealed along all three edges whereby a completely andhermetically sealed structure is provided. In order to permit removal ofa portion of this inner bag or envelope of completely sealed characterand still retain a sufcient marginal portion for resealing, it isdesirable to have the liner extend slightly longer than this wasnecessary or customary in prior practice. On the other hand, since forsimplicity of manufacture it is desirable to heat-seal the liner whileresting on the carton blank of the container the upper flaps associatedAwith `the blank have to be slightly extended corresponding to theextension ofthe liner. This makes it possible to cut off a strip of thefinished and collapsed carton and liner in a single operation andthereby to prepare the container for filling, as this will be explainedmore fully as the description proceeds.

Referring now more particularly'to the drawings, a preferred embodimentof the invention will be explained. Fig. 1 illustrates a plan view of acarton blank I0, having ya plurality of score lines defining main panelsil and I2 and end panels I3 and Ill. Flaps I5 and IG are hingedlyconnected with main panels Il and l2, respectively. Flaps Il and I8 areprovided at the'ends of end panel I3 and similar flaps I9 and 20 areprovided at the ends of end panel Ill. It will be noted in Fig. l thatmain panels II and I2 are connected by means of 'a bottom panel 2l ofspecial character having a medial score line Zia permitting the cartonblank to be folded so as to bring the main panels into a substantiallyregistering position. Main panel I 2 has glue flaps 22 and 23 at the twolateral edges thereof. End panels I3 and I4 have medial score lines 24and type is disclosed in my copending application, Serial No. 255,030,filed on Feb. 7, 1939, so that no detailed description of its operationwill be necessary. It will be sufficient to state that by bringing themain panels into superposed registering position and by folding back theportions of the end panels beyond medial lines 24 and 25, such portionsof the end panel may be glued to glue flaps 22 and 23 of main panel I2whereby a flattened six sided box is obtained capable of being convertedor squared-up into a rectangular package. It is to be observed that topflaps I5, I1 and I 9 are considerably longer than the correspondingflaps I 8, 20 and 2 I. The object of the accentuated length of these'flaps is to provide a backing surface of a liner of likewise accentuatedlength which at a later time is converted into a structure of standardlength by cutting off the excess length, as this will appear more fullyhereinafter.

The first step in the preparation of my improved sterile collapsiblecontainer is to adhesively secure a liner 26 to the carton blank bymeans of adhesive lines 21. As it will be best observed in Fig. 2, thisliner is generally constituted of a 25 respectively. A carton blank ofthis general i The liner has such dimensions as to extend from theregion of score line 2Ia oi' carton blank III structure depicted in Fig.3. This operation will` fold the liner along its transverse 'medial lineand will bring its edges into registering position. At the same timemain panels I I and I2 will like wise be brought into a superposedregistering lposition and will have the folded' liner therebetween.

pressure in separate operationsM along each of the A exposed marginalstrips of the folded liner. As a rule, however, I prefer to apply alcontinuous U-shaped seam to these marginal portions by a means of aspecial U-shaped heat-sealing member so that a continuous hermeticalseal 28 will be obtained. This seal converts the folded'gliner sheet 26into a completely sealed envelope into which the access of any externalsubstance, including that of atmospheric air, is prevented. End panelsI3 and I4 are now folded along their medial score lines] 24 and 25 andtheir inner surface is adhesively secured to glue flaps 22 and 23 ofmain panel I2. It will be noted that folding of the end panels alongtheir medial score lines will cause folding of the sealed envelope aboutthe edges of glue flaps 22 and 23 so that a fold will be introduced intothe portion of the envelope before the seam. This will protect the seamfrom the effect 'of internal pressure after the container has beenfilled and sealed.

The finished container in its collapsed form, as it is shipped andstored, is shown in Fig. 4. Due

to the fact that in this condition theyinner enve- 1 lope is completelysealed, the container may be preserved in the sterile conditionindefinitely. A further interesting result of this completely sealedstructure is that the external atmospheric pressure prevents squaing-uplthe collapsible container due to the fact that no air is admittedthereto and squaring-up would create a vacuum therein. In other words,the containers of the invention will be automatically maintained in acompletely fiattened condition which is an important advantage in thatit reduces the space required for shipping and storage of the containersto a minimum. K

When it is desired to use and to iill the container, it is necessary toprovide a lling opening therein through which first air may be admittedinto the interior, permitting squaring-up of the container andsubsequently the filling operation may be performed and the filledcontainer may be resealed. The filling opening may be provided invarious ways, such as by punching a small opening or by cutting oif oneof the edges of the container, as this is indicated by dotted line 23 inFig. 4. It is preferred, however, to cut olf a Laterally the linerextends across.

transverse marginal portion ofthe inner envelope, and the containershown in the drawings is especially adapted for this type ofmanipulation. According to this preferred procedure, a top marginalstrip 30 of the collapsible container is removed by cutting the,container along a line 3I- indicated in dotted lines in Fig. 4. Thisoperation will remove the topl marginal portions of both the innerenvelope and of the external carton. 'I'his will have the result ofadmitting air into the interior of the envelope and at the same timeremoving the excess portions of top flaps I5, I1 and I3 which will nowhave the same length as the corresponding bottom flaps I6, 20 and2l. Theflattened container may now be squared-up and assumes the shapeillustrated in Fig. 5. It will be noted that the squared-up and openedenvelope has two lateral fins 32 and 33 which are nattened in thedirection of the end panels I3 and I4. The material to be packaged',such as, milk, cream, or some other commodity, may now be introducedthrough a filling spout 34 connected with a storage tank and with asuitable measuring device which introduces a predetermined unitaryamount of the material to be packaged.

I have found that in order to provide a her metical seal of the packageand to positively prevent leakage from such sealed package, it iscritically important to provide a seal of such character in which onlytwo layers of material are placed into a face to face relation and fromwhich intervening layers, re-entrant folds and similar danger points ofleakage are positively eliminated. Therefore, in order to obtain thedesired hermetical seal and the face to face relationship of only twolayers of material in the mouth portions of the envelope, a specialprocedure has to be used. This consists in bringing together theflattened mouth portions ofthe envelope into a face to face relation andfolding down the'resulting flattened mouth portions into the planedelined by the hinge lines of the top flaps. Attention is directed tothe circumstance that this folding down of the flattened `marginalportions is possible only in the direction in which iins 32 and 33 arepointing due to the fact that these fins act much in the same manner asreinforcing ribs which are almost completely rigid inother directions.This operation provides the structure depicted in Fig. 6. Of course, thetop marginal strip 35 of the package embodying the invention may beheat-sealed already in this position by means of a heat-sealing deviceof suitable character. Generally, I prefer, however, to fold this region35 to be heat-sealed verticallyupwards (Fig. 7) whereby it is morereadily accessible to a heat-sealing member and backing member ofstandard type. It will also be noted that region 35 represents'acompletely at seal area in which even the terminal portions of ns 32 and33 are straightened out in the direction of the rmouth walls of theenvelope whereby the critically important completely fiat seam may bereadily obtained. After heat-sealing, the resulting tabs 36 and 3l maybe `folded towards each other along lines 3s ao as as this is showrrI inFig. s and the flaps of the carton may be closed and adhesively securedthereabout. This completes the package of the invention.

It will be noted that the present invention provides importantadvantages. The method of the invention makes it possible for the firsttime in the history of the art to maintain the originally contaminationof the interior ofthe container by micro-organisms. Of course, this isof extreme importance particularly when it is desired to employcollapsible containers for the purpose of packaging milk, cream andsimilar foodstuffsand may be manufactured, sold and used on a practicaland commercial scale at a very low price. f

Although the present invention has been described in connection with afew preferred embodiments thereof, variations and modifications lmay beresorted to by those skilled in the art without departing from theprinciples of the present invention. I consider all of these vanationsand modifications as within the true spirit and scope of the presentinvention, as disclosed in the foregoing description, and defined by theappended claims.

I claim:

1. The method of packaging foodstuffs and similar commodities in asubstantially sterile condition which comprises providing asubstantially iiuid-tight and sterile collapsible container adapted tobe hermetically sealed, collapsing said container, hermetically sealingsaid collapsed container to prevent the entrance of foreign and septicmatter thereinto, and maintaining said container in a hermeticallysealed condition until such timeas it is filled with a commodity wherebythe atmospheric pressure will maintain said container in completelycollapsed position. I 2. The method of packaging foodstus and similarcommodities, including milk, in a substantially sterile condition whichcomprises providing a substantially fluid-tight and sterile collapsiblecontainer adapted to be heat-sealed, co1- lapsing said container,hermetically heat-sealing said collapsed container to positively preventthe entrance of foreign and septic matter into the interior thereof, andmaintaining said container in a. hermetically sealed condition untilsuch time as it is filled with a commodity whereby the atmosphericpressure will maintain said container in completely collapsed position.

.3. The method of packaging milk and similar liquid perishablecommodities in a substantially sterile condition which comprisesproviding a. substantially fiuid-tight and sterile collapsible containerfusible at least on the inner surface thereof, collapsing saidcontainer, applying heat and pressure to a predetermined region of saidcontainer to hermetically seal the same and thereby to positivelyprevent the entrance of detrimental matter into the interior of saidcontainer, maintaining lsaid container in a hermetically sealedcondition until such time as it is filled whereby the atmosphericpressure will maintain said container in completely collapsed position,opening said hermetically sealed container, filling said open containerwith the commodity to be packaged, and then hermetically resealing saidcontainer.

4. The method of aseptical packaging which comprises providing a fiatand collapsed envelope fluid-tight on at least the inner face thereof,hermetically sealing said collapsed envelope to prevent the entrance ofdeleterious microscopic matter thereinto, maintaining said envelope insuch sealed condition until the time of filling whereby` the atmosphericpressure will maintain said envelope in completely collapsed position,opening said envelope immediately prior to filling, thereafter fillingsaid opened envelope with contents, and then hermetically resealing saidfilled container.

5. The method of aseptical packaging which comprises providing acollapsed envelope fiuidtight and fusible on .at least the inner facethereof, heat-sealing said envelope along its marginal portions toprevent the entrance of microorganisms thereinto, `maintaining saidenvelope in such sealed condition until the time -of filling therebyholding the inner Walls thereof in a face and sterile collapsiblecontainer adapted to be heat-sealed, collapsing said container to bringits opposed walls into a face to face position and to reduce itsvolumetric content substantially to zero, hermetically heat-sealing saidcontainer while in .such collapsed condition whereby the externalatmospheric pressure will maintain said container in collapsed conditionand entrance of deleterious microscopic matter into the interior thereofis positively prevented, and maintaining said container in a collapsedand hermetically sealed condition until such time as it is filled with acommodity.

7. The method of aseptical packaging which comprises providing anenvelope fluid-tight and fusible on at least the'inner face thereof,collapsing said envelope to bring its opposed walls into a face to faceposition and to vreduce its internal capacity substantially to zero,hermetically heat-sealing said envelope along its marginal portionswhereby the external atmospheric pressure will maintain said envelope inc'ollapsed condition and the entrance of microorganisms into theinterior of the envelope is positively prevented, maintaining saidenvelope in such col` `lapsed and sealed condition until the time ofthrough said filling opening, and' then hermetically resealing saidfilling opening.

8. The method of aseptical packaging which comprises providing a fiatenvelope constituted of a sheet .iiuid-tight and fusible on at least oneface thereof folded along a line to have its edges in a substantiallyregistering position, heat-sealing said envelope along three marginalstrips to provide hermetic closure thereof and to prevent the entranceof organic and inorganic impurities, maintaining said envelope in suchsealed condition until the time of filling thereby holding the innerwalls thereof in a face to face position by means of the atmosphericpressure, cutting off a marginal strip of material from said envelopetoremove one of said sealed marginal strips and to provide a fillingopening, thereafter filling said envelope with contents through saidfilling opening, and then resealing said filling opening by aheat-sealed seam parallel with said cut-off marginal strip.

9. 'Ihe method of aseptical packaging which velope and the attachedcarton in collapsed position, providing a filling opening in said closedenvelope, squaring-up said carton thereby simultaneously squaring-upsaid envelope, thereafter filling said envelope with contents throughsaid filling opening, and then resealing said. filling opening andclosing the flaps thereabout.

10. The method of aseptical packaging which comprises providing a flatfolded carton having at least four parallel score lines and closingflaps at the ends thereof, said carton having adhesively secured to itsinner surface a liner fluid-tight and fusible at least on the innersurface thereof longitudinally projecting beyond the hinge lines ofsaidclosing iiaps and free of attachment thereto, heat-sealing saidliner along its longitudinal and its transverse edges to convert it intoa hermetically sealed envelope protected against the en.

trance of microorganisms'into the interior thereof, maintaining saidenvelope in such hermetically ysealed condition until the time offilling whereby the atmospheric pressure will maintain both the envelopeand the attached carton in collapsed position, cutting oif the topsealed portion of said envelope to provide a filling opening,squaring-up said carton thereby simultaneously squaring up saidenvelope, thereafter filling said envelope with contents through saidfilling opening, and then sealing said filling opening and closing saidflaps.

11. 'I'he method of aseptical packaging which comprises providing a fiatfolded carton having at least four parallel score lines at the endsthereof, said carton having adhesivelyy secured to its inner surface aliner huid-tight and fusible at least on the inner surface thereoflongitudinally projecting beyond the hinge lines of said closing flapsat least at one end of said carton and free of attachment thereto,heat-sealing said liner along a U-shaped strip adjacent to itslongitudinal and its transverse edges to convert it into a hermeticallysealed envelope protected against the entrance of microorganisms intothe interior thereof, maintaining said'envelope in such hermeticallysealed condition until the time of iilling whereby theatmosphericpreslsure will maintain both the envelope and the attachedcarton in collapsed position, providing a restricted opening in the topportion of said envelope to permit the entrance of air thereinto,squaring-up said carton thereby simultaneously squaring-up saidenvelope, cutting off the top marginal portion of said envelope toprovide a filling opening, thereafter filling said envelope withcontents through said filling opening, and then heat-sealing saidiilling opening and closing said iiaps.

12. The method of aseptical packaging which comprises providing a flatfolded carton having a plurality of longitudinal lines deiining a pairofend panels with medial crease lines therein and a pair of main panelsand having:l closing aps at the end of at leastsome of said panels, saidcarton having adhesively secured toits inner sur face a linerfluid-tight `and fusible at least on the inner surface thereoflongitudinally projecting beyond the hinge lines of said closing flapsand disconnected .therefrom at least at one end of said panels,heat-sealing said liner along its longitudinal and transverse edges toconvert it into a hermetically sealed envelope protected against theentrance of microorganisms into the interior thereof, maintaining saidenvelope in lsuch hermetically sealed condition until the time offilling whereby the atmospheric pressure will maintain both the envelopeand the attached carton in collapsed position, cutting off one of thevterminal portions of said flat folded carton and thereby simultaneouslycutting olf a sealed terminal portion of said envelope to permit theentrance of air thereinto, squaring-up said carton therebysimultaneously squaring-up said envelope, thereafter filling saidenvelope with contents, and then resealing said envelope and closingsaid flaps.

13. The method of making a sterile package which comprises bringingtogether the marginal regions of a liiexible material into a contactingrelation, and sealing suchmarginal regionsv to provide a completelysealed structure maintained -in collapsed position by the atmosphericpressure whereby contact of the inner surfaces of such structure withthe atmosphere is prevented,

' said structure being adapted to be opened immediately prior to fillingand to be resealed after filling. a 4

14. The method of making a sterile packaging medium which comprisesbringing together the marginal regions of a sheet integrally constitutedof a thermoplastic material into a contacting relation, and applyingheat and pressure to such marginal regions to hermetically heat-seal theresulting structure and to maintain the same in collapsed position bythe atmospheric pressure whereby contact of the inner surfaces of suchstructure with the atmosphere is positively prevented, said structurebeing adapted to be opened immediately prior to filling and to beresealed after filling.

15. The method of making a sterile packaging unit which comprisesfolding over a iiexible sheet fluid-tight and fusible on at least oneface thereof along a line to bring its edges into a substantiallyregistering position, and heat-sealing said folded sheet along themarginal regions of said registering edges to provide a hermeticallysealed envelope proof against the entrance of deleterious matterthereinto, said sealed envelope being held in collapsed position by theatmospheric pressure and adapted to be preserved indefinitely in itsoriginal-sterile condition and capable of being opened prior to fillingand of being resealed after filling.

16. The method of making a sterile packaging unit which comprisesforming a xfour-walled carton blank having medial score lines in twooppositely disposed Walls thereof, adhesively securing a substantiallyrectangular liner to said blank having at least its top surfaceiiuid-tight and fusible, simultaneously folding over said carton blankand liner to form an envelope open at three edges, heat-sealing all ofthese three edges of saidenvelope While it is resting on said blank tohermeticallyseal the same and to positively prevent the admittance ofdeleterious matter thereinto, and subsequently adhesively securing theends of said carton blank together whereby the atmospheric pressure willmaintain both the l envelope and the attached carton in collapsedposition, said hermetically sealed envelope being

